Search Results (989)

Mythimna separata, an important insect pest of grain crops, exhibits density-dependent prophylaxis (DDP). Most studies have focused on DDP from the perspective of immune system regulation. In this report, we show that two cuticular protein genes, MsCP1 and MsCP2, are involved in DDP of M. separata. MsCP1 and MsCP2 were highly expressed in 4th and 5th instar larvae of the M. separata gregarious high-density phase as compared to solitary, low-density individuals. The expression levels of MsCP1 and MsCP2 were significantly higher in the cuticle of gregarious larvae than in solitary individuals. When MsCP1 and MsCP2 were knocked down by star polycation (SPc) nanocarrier-mediated RNA interference (RNAi), the expression levels of the two genes were significantly downregulated in gregarious larvae as compared to dsGFP/SPc-treated gregarious larvae but were not significantly different from dsGFP/SPc-treated solitary larvae. Furthermore, silencing of MsCP1 and MsCP2 caused abnormal molting, alterations in ultrastructure, and reduced cuticle thickness in gregarious larvae. The mortality rates in dsMsCP1/SPc- and dsMsCP2/SPc-treated gregarious larvae were significantly higher after infection with the entomopathogenic fungus Beauveria bassiana as compared to the dsGFP/SPc-treated gregarious larva but were not significantly different from mortality rates in dsGFP/SPc-treated solitary larvae. Taken together, these findings suggest that upregulation of MsCP1 and MsCP2 are associated with resistance of gregarious M. separata to B. bassiana. These results broaden our understanding of insect DDP and are of great significance in the biological control of M. separata. Full article

The use of Steinernema carpocapsae infective juveniles as biological control agents is a long-standing practice, yet the oral impact of their secreted venom proteins on crop pests remains largely unknown. We evaluated the oral toxicity of S. carpocapsae venom proteins against Spodoptera frugiperda using artificial diet assays. Ingestion caused significant dose-dependent toxicity in early-instar larvae, resulting in mortality and a prolonged developmental duration. Carry-over effects were profound; treated pupae were smaller and malformed, with only 19% of larvae fed on 1000 ng g⁻¹ venom protein-supplemented diet reaching adulthood compared to 92% in controls. Surviving adults lived 30% fewer days and laid over 90% fewer morphologically normal eggs. These physiological disruptions coincided with elevated oxidative stress and detoxification enzyme activity, suggesting the venom induces oxidative and detoxification responses, which may be associated with the observed phenotypic alterations. This study provides the first demonstration of the oral toxicity of entomopathogenic nematode venom proteins, positioning them as a promising resource for the discovery of novel insecticidal proteins for sustainable pest management. Full article

(1) Background: Potentially arthropod-pathogenic and plant-associated Metarhizium fungi are of high interest for basic research, biological pest control and plant growth promotion. Unambiguous species delineation enabling the taxonomic assignment of new isolates and the identification of new Metarhizium species is of crucial importance for both research and application. Recently, the new species Metarhizium hybridum and Metarhizium parapingshaense were introduced on the basis of phylogenomic studies. (2) Methods: Neighbor- joining and Bayesian inference-based phylogenetic reconstruction of ribosomal intergenic spacer (rIGS) sequences were used to critically evaluate new species introductions. A species-discriminating diagnostic PCR tool for Metarhizium was adapted to M. hybridum and M. parapingshaense. GenBank database mining was performed to identify cryptic descriptions of the new species. (3) Results: The introduction of M. hybridum and M. parapingshaense was corroborated by rIGS sequence comparison. Data mining revealed cryptic first descriptions of M. hybridum from Canada, China, Colombia, Costa Rica, Cuba, Honduras, Mexico, New Zealand, the USA and the Philippines, and of M. parapingshaense from China, India, Japan, the Philippines and South Korea. (4) Conclusions: Results support the reliability of rIGS as a single taxonomic marker for species-level identification of Metarhizium fungi. Species-discriminating diagnostic PCR was successfully adapted to enable the sequencing-independent identification of the confirmed new species M. hybridum and M. parapingshaense. Full article

The management of Culex pipiens (Diptera: Culicidae), key vectors of arboviruses like West Nile virus, necessitates sustainable alternatives to chemical insecticides. This study screened indigenous entomopathogenic fungi (EPF) from forest soils in Achaia, Greece, for their larvicidal efficacy against Cx. pipiens biotype molestus. Fifteen fungal isolates were obtained via insect baiting and identified as Beauveria and Metarhizium species. A comprehensive bioassay at 1 × 10⁸ conidia mL⁻¹ revealed significant variation in pathogenicity after 72 h. Two isolates, Beauveria bassiana (BB) (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (K3(1)) (Hypocreales: Clavicipitaceae), exhibited the highest virulence among the tested isolates, each causing 60% mortality with a rapid median lethal time (LT₅₀) of ~18.5 h. Survival analysis, Cox modeling, and non-linear kinetic modeling (Gompertz/Richards) classified three distinct virulence clusters: high/rapid, moderate/consistent, and low/delayed. A pathogenicity network analysis and a composite virulence index further validated BB and K3(1) as the most effective candidates. These results demonstrate the high isolate specificity of fungal efficacy and underscore the importance of screening local fungal diversity. The identified high-virulence isolates represent promising, environmentally sound candidates for the development of targeted biopesticides. Future research should focus on formulation for aquatic environments and integration into resistance-resilient integrated vector management programs. Full article

Bursaphelenchus rainulfi is a pine-associated, non-pathogenic nematode that serves as a motile comparative species for evaluating nematophagous fungi. We investigated the in vitro biocontrol activity of Purpureocillium takamizusanense strain PMEPF27, originally isolated from insect cadavers in Taiwan, against mixed motile stages of B. rainulfi. Identity of the fungus was confirmed by morphology and ITS/EF-1α sequencing. Nematodes were exposed in liquid suspension to PMEPF27 conidia, with sterile water as the negative control and fluopyram as the positive control. Mortality was monitored over 7 days, and scanning electron microscopy was used to observe fungus–nematode interactions. PMEPF27 caused significantly higher mortality than the water control, reaching ~80% by day 7, and showed surface disruption of nematode cuticles, although no direct spore penetration was observed. These findings expand the nematophagous profile of P. takamizusanense beyond egg and sedentary stages, validate B. rainulfi as a motile comparative species in pine-nematode bioassays, and highlight PMEPF27 as a promising candidate for biocontrol development. Full article

Nematodes in the genus Oscheius (Rhabditidae) have traditionally been regarded as free-living bacteriophagous or necromenic associates of insects. Over the past two decades, however, multiple Oscheius species and isolates have been shown to express facultative pathogenicity toward insects and, in some cases, parasitism of mollusks. This has stimulated interest in Oscheius as a complementary group of biological control agents that may function under conditions limiting classical entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis. Here, we synthesize current knowledge on Oscheius taxonomy and diversity, life-history strategies, bacterial associations and virulence mechanisms, evidence for control of insect and mollusk pests, and recent advances in chemo-ecology relevant to host finding. We emphasize that Oscheius represents a continuum of ecological strategies, and we adopt conservative terminology in which “entomopathogenic” is reserved for Oscheius species/isolates that meet operational criteria of insect pathogenicity. Finally, we highlight key barriers to wider implementation—strain variability, bacterial partner instability, non-target and community effects, and production/quality control needs—and propose research priorities for the development of robust, field-reliable Oscheius-based biocontrol. Full article

Biological control agents (BCAs) have emerged as a key strategy to mitigate maize diseases while reducing dependence on synthetic agrochemicals, which pose risks to human health, ecosystems, and microbial diversity. This review synthesizes advances from 63 research articles published between 2020 and 2025, selected through a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach to capture studies with in vitro, greenhouse, or field validation. The analysis highlights major fungal and bacterial threats to maize production and evaluates BCAs, including Bacillus, Trichoderma, Streptomyces, and entomopathogenic or endophytic microorganisms, tested across multiple experimental levels. Results show that many agents demonstrate strong antagonism under controlled conditions, promoting plant growth, reducing pathogen incidence, and lowering mycotoxin contamination. Field trials, however, reveal inconsistent performance due to environmental variability, formulation instability, and incomplete understanding of strain-specific mechanisms. Emerging approaches such as microbial consortia, metabolite-based biocontrol, biochar–microbe combinations, and evaluations under dual-stress conditions offer promising avenues to improve reliability and expand applicability. Overall, the review underscores that although microbial biocontrol holds substantial potential for sustainable maize protection, progress toward scalable implementation requires integrating omics-based characterization, optimized formulations, genotype-specific evaluations, and multi-season field trials to bridge the gap between laboratory efficacy and field performance. Full article

Peri-urban ecosystems represent underexplored habitats rich in entomopathogenic fungi (EPF) that can serve as valuable resources for managing insect pests. This study characterized the EPF communities in two peri-urban sites near Patras, Greece (Dasyllio and Elos), during 2018–2019. Soil samples were collected seasonally, and fungi were isolated using insect baiting with Tribolium confusum Jacquelin du Val and Sitophilus zeamais Motsch., a selective method favoring generalist, fast-acting entomopathogens. A total of 814 isolates were recovered. Of a randomly selected subset (n = 177) subjected to molecular identification, 46.9% were characterized as known EPF, while 53.1% were classified as putative EPF based on taxonomic affiliation (ITS sequence similarity ≥ 99%), pending confirmation of pathogenicity. The Dasyllio site yielded more isolates (63.4%) than Elos (36.6%). Seasonal trends strongly influenced EPF occurrence, with infective fungi peaking in spring and summer (p < 0.001), while community diversity remained stable throughout the year, with the highest evenness (Evenness Index = 0.93) observed in autumn. These results highlight peri-urban green spaces as reservoirs of diverse and ecologically stable EPF, suggesting their potential as sources of biocontrol agents for future development and seasonal integration into pest management strategies. Full article

This study evaluated entomopathogenic nematodes (EPNs) isolated from a cacao agroforestry system in the Peruvian Amazon, focusing on their molecular characterization and efficacy against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae. Thirteen EPN isolates were obtained from 50 soil samples using the Galleria mellonella baiting technique. Mortality assays revealed significant differences among isolates at 24, 48, and 72 h, with isolates 11N-A4 and 8N-B1 being the most virulent, achieving maximum mortalities of 100% and 96.3% at 72 h, respectively. Median lethal time (LT₅₀) values indicated rapid action of these isolates on G. mellonella larvae, with 33.3 h for 11N-A4 and 32.4 h for 8N-B1. Molecular identification using ITS, D2–D3 (LSU), and COI markers confirmed the isolates as Heterorhabditis sp. (11N-A4) and Heterorhabditis amazonensis (8N-B1). In bioassays with S. frugiperda larvae, both EPNs exhibited dose- and time-dependent mortality. H. amazonensis showed rapid action, reaching 100% mortality at the highest dose (60 IJs/larvae) within 48 h, whereas Heterorhabditis sp. displayed a gradual, sustained increase, attaining 91% mortality at 72 h. Median lethal dose (LD₅₀) and LT₅₀ values reflected the efficiency of both isolates, with Heterorhabditis sp. achieving lower LD₅₀ at later stages and shorter LT₅₀ at low-to-intermediate doses. These findings highlight the potential of Heterorhabditis sp. and H. amazonensis as effective biocontrol agents adapted to local conditions and represent the first report of H. amazonensis in Peru. Further studies under field conditions are required to confirm their suitability for incorporation into integrated pest management strategies in the Peruvian Amazon. Full article

In the complex interplay among parasitic wasps, their insect hosts, and pathogenic microbes, the system involving Sclerodermus guani (Hymenoptera: Bethylidae) (a parasitoid wasp), Monochamus alternatus (Coleoptera: Cerambycidae) (the pine sawyer beetle, its host), and Beauveria bassiana (Hypocreales: Cordycipitaceae) (a fungus) presents a unique scenario where wasp offspring develop within a nearly sealed host gallery. This nursery is vulnerable to fungal invasion, often introduced by the foraging female wasps or M. alternatus itself, creating a three-way interaction where the fungus can infect both M. alternatus and S. guani. To assess how the route and timing of fungal exposure impact the S. guani population, we simulated this system by introducing different concentrations of B. bassiana either directly to the female wasps or to M. alternatus prior to parasitism. We further examined the effect of exposure timing by applying the fungus at different developmental stages of the S. guani offspring. Key population parameters, including the reproductive capacity of female wasps, the survival and developmental fitness of S. guani offspring and the germination period of hyphae, were measured. The results indicated that the most severe damage to populations of S. guani occurs when its host, M. alternatus, is infected by B. bassiana. Among the various developmental stages, S. guani offspring exhibited the greatest vulnerability during mid-to-late larval stages, whereas the egg and pupa within cocoon stages demonstrated a higher tolerance. We conclude that both the pathway and the timing of fungal exposure are critical factors influencing its impact. These findings provide valuable insights for optimizing the integrated use of biological agents in pest management, informing strategies that mitigate adverse effects on beneficial parasitoid wasps. Full article

The white-backed planthopper (Sogatella furcifera) is a major pest in rice-growing regions worldwide. It severely limits rice production through piercing–sucking feeding, oviposition injury, and by efficiently transmitting the Southern Rice Black-Streaked Dwarf Virus (SRBSDV). Previous studies demonstrated that the dark septate endophytic fungus Ochroconis guangxiensis strain X22 exhibits control activity against SRBSDV. To further evaluate its biocontrol potential, this study investigated the effects of the X22 strain on S. furcifera, the primary vector of SRBSDV. In this study, we established an X22–rice symbiotic system to evaluate its effects on the biological traits of S. furcifera. The results showed that, compared with a clear water treatment, the X22 strain significantly reduced the feeding amount (29.02%), egg-laying amount (12.30%), and hatching rate (11.58%) of S. furcifera. Gene expression analysis showed that the relative expression levels of the Target of Rapamycin (TOR) and vitellogenin (Vg) genes in one-day-old S. furcifera from the X22 treatment group were modestly downregulated, although no significant differences were detected compared with the control. Enzyme activity assays revealed that between 72 and 120 h post-treatment, the activities of detoxification enzymes, including carboxylesterase (CarE) and acetylcholinesterase (AChE), generally declined following X22 exposure. In contrast, the activities of protective enzymes, superoxide dismutase (SOD) and catalase (CAT), as well as certain digestive enzymes, α-amylase (α-AL) and trypsin, were induced. Conversely the activities of glutathione peroxidase (GSH-Px) and lipase (LPS) were suppressed. However, the physiological mechanisms underlying its effect on S. furcifera remain unclear. Collectively, these results demonstrate that the O. guangxiensis X22 strain inhibits S. furcifera reproduction by disrupting its physiological metabolism through multiple pathways, providing a mechanistic basis for its development as an environmentally friendly biocontrol agent. Full article

Cordyceps militaris is an entomopathogenic fungus traditionally used in Asian ethnomedicine and increasingly investigated for its potential health-promoting properties, including immunomodulatory and anti-inflammatory activities. In recent years, it has gained attention as a dietary supplement with possible applications in sports nutrition. This narrative review summarizes and critically evaluates the current human evidence regarding the ergogenic and post-exercise recovery effects of C. militaris supplementation in healthy individuals. A structured database search was conducted using predefined eligibility criteria, and the methodological quality of included studies was appraised through domain-based risk-of-bias assessment. Five intervention studies published between 2017 and 2024, comprising 321 participants aged 16–35 years, were identified. Supplementation protocols ranged from 1 to 16 weeks, with daily doses of 1–12 g administered either as isolated fungal material or as a part of multi-ingredient formulations. Assessed outcomes included indices of aerobic performance and exercise capacity, such as maximal or peak oxygen uptake (VO₂max/VO₂peak), time to exhaustion, power output, running performance, and maintenance of peripheral oxygen saturation during high-intensity exercise. Several studies also evaluated biochemical markers related to muscle damage and inflammatory responses, including creatine kinase, blood urea nitrogen, and white blood cell counts. Although some studies reported improvements in selected performance and recovery parameters, the findings were inconsistent. The certainty of the evidence is limited by small sample sizes, heterogeneity of participants and exercise protocols, insufficient reporting of randomization, lack of trial registration in most studies, absence of standardized preparations with quantified bioactive constituents, and the use of multi-ingredient supplements. Well-designed randomized controlled trials using chemically characterized preparations and homogeneous athletic populations are required to clarify the efficacy and practical relevance of C. militaris in sports nutrition. Full article

Cylas formicarius is a significant quarantine pest worldwide, causing year-round outbreaks in tropical and subtropical regions. This pest is characterized by a highly cryptic nature, a high reproduction rate, and broad environmental adaptability, which makes it difficult to control. Frequent use of pesticides is not cost-effective, as it brings the accompanying effects of pesticide residues and environmental pollution. With the rapid development of green agriculture, biological control has become an important component in an integrated green management system for C. formicarius. Therefore, this paper critically reviews the research progress in insect pathogenic microorganisms, plant-based pesticides, natural enemy insects, insect sex pheromones, transgenic technology, as well as the screening, identification, and breeding of insect-resistant varieties. The aim is to provide theoretical references for the research and application of sustainable management of C. formicarius. Full article

The South American tomato pinworm, Tuta absoluta, is a devastating invasive pest that threatens global tomato production, while entomopathogenic nematodes (EPNs) represent promising biocontrol agents. Because a detailed understanding of the molecular basis of the insect immune response is crucial for uncovering how hosts detect and counteract nematode infection, such knowledge may reveal weaknesses exploitable for improved control strategies. However, the molecular mechanisms governing the immune interaction between this pest and EPNs remain poorly understood This study investigated the biocontrol potential of a native Chinese EPN strain, Heterorhabditis indica CQ7-2, against T. absoluta and delineated the host’s molecular immune responses via a time-course transcriptomic analysis. Bioassays revealed that H. indica CQ7-2 LC₅₀ was 1.35 IJs per larva. Comparative transcriptome profiling of larvae revealed that the EPN infection was associated with transcriptional patterns consistent with immunosuppression. Key genes involved in humoral and cellular immunity were significantly suppressed during the early and middle infection stages. Although a widespread upregulation of immune genes occurred after 18 h post-infection (hpi), it was insufficient to prevent host mortality. These findings demonstrate that the virulence of H. indica CQ7-2 is underpinned by associated with modulation of key immune pathways, leading to an ineffective defense response. This work provides deep insights into the molecular arms race between an invasive pest and a native EPN, supporting CQ7-2 as a promising biocontrol agent and providing a framework for understanding host-EPN interactions. Full article

Monilinia laxa and Colletotrichum fioriniae are major fungal pathogens causing brown rot and anthracnose in stone fruits and shell fruits, leading to significant economic losses. Chemical fungicides are widely applied but can result in resistance development, environmental contamination, and food safety concerns. Biological control using entomopathogenic bacteria (EPB) of the genus Photorhabdus has emerged as an eco-friendly alternative. This study evaluated the in vitro antifungal activity of selected Photorhabdus species (P. kayaii 1723B, P. temperata 3017, P. cinerea 3086, P. laumondii 3196, and P. thracensis 3210) against M. laxa (M3) and C. fioriniae (VV081) using drop-to-drop confrontation and poisoned agar assays. Effects of fermentation time, preparation mode (original vs. centrifuged and filtered), and concentration (5, 10, 20%) were examined. Species-specific inhibition was observed, with Median Inhibition Index values indicated relatively higher antifungal activity for P. thracensis 3210 against M. laxa (0.718) and C. fioriniae (0.552), followed by P. cinerea 3086 (0.643 and 0.552) and P. kayaii 1723B (0.629 and 0.541). Fermentation time and preparation mode influenced antifungal activity in a strain-dependent manner, with longer fermentation periods and original culture preparations generally showing stronger inhibitory trends. Higher concentrations, especially 20%, were often associated with increased inhibition, although the magnitude of these effects varied among strain–pathogen combinations. Overall, these findings demonstrate that the strain- and pathogen-specific nature of antifungal responses in Photorhabdus, supporting their potential as components of targeted biological control strategies rather than uniform broad-spectrum agents. Full article